DE19839290A1 - Gear ratio change control-regulating system for vehicle automatic gear box drive - Google Patents

Abstract

The system has gear settings (G1,G2,G3), which transmit the engine torque on a drive shaft. Frictional engaging elements (K1,K2,K3,B1,B2) work for a selective setting of a gear changing ratio in an automatic gear box (1). The control/regulating facility includes a first step (1,S28-S24) for determining the command (QTRQ). Such that an actual slip rate of the frictional engaging elements, which set the instantaneous gear ratio (eCLO) to converge to give the first desired slip rate (ECL02). Switching solenoid valves (SA-SE) are provided in the oil pressure control-regulating circuit (300).

Description

The present invention relates to a Gear ratio switching control system for an automatic Vehicle transmission, and in particular it relates to a system for Control / regulate the supply of an oil pressure by switching solenoid valves frictionally engaging elements that change the current gear Set up (gear ratio), of which when shifting up is switched off.

In an automatic vehicle transmission, which has a plurality of Includes gear trains, the engagement or disengagement of the frictionally engaging or attacking elements such. B. hydraulic clutches or brakes or equivalent elements, controlled / regulated by switching solenoid valves to enable that a gear (gear ratio) from a plurality of Gear trains is selected, which puts the machine power on the Vehicle is transmitted. In particular, the upshift or Shift down by disengaging frictionally engaging Elements for the current gear stage (gear ratio) which is switched while performed smoothly attacking elements for the next gear (Gear ratio), into which is switched, frictionally be indented, each by energizing or de-energizing the Switching solenoids.

To perform smooth shifting without delay, it is required to set exactly times when the frictional  engaging elements of the current gear (gear ratio) be disengaged and the frictionally engaging elements of the next gear (gear ratio) and the Shift sequence starting from disengaging the friction engaging elements of the current gear (gear ratio) until fully engaging the frictionally engaging Next gear elements (gear ratio) too control / regulate. The Japanese laid-open patent teaches for this purpose No. 62 (1987) - 246,653 lowering the clutch oil pressure of the momentary gear so that the clutch slips to to absorb the moment of inertia.

However, it is difficult in the prior art to determine when the Clutches of the current gear (gear ratio) too start hatching. For this reason, the applicant suggests in the Japanese Patent Laid-Open Nos. 6 (1994) - 307,524 and No. 8 (1996) - 277,921, the switching control sequence period for the current gear (gear ratio) in several stages or Subdivide steps and current clutch oil pressure Lower gangs (gear ratio) and clutch slip in Response to the detected throttle opening and that Regulating the machine output torque in feedback.

However, the clutch slip is affected by the condition of the clutch e.g. B. aging, clutch plate temperature, gear shifting and some other parameters are affected. As a result, it changes the time at which the clutches slip with the Clutch states even when the oil pressure is as desired is controlled. Furthermore, the oil pressure should be increased so that the Operating life due to slippage to a lesser extent is affected. It is therefore desirable to determine the period of the To reduce clutch slip and thus the shift control  Shorten the sequence period of the current gear. It won't just increase the clutch life, but so does that smoothly shifting to the next gear Enable (gear ratio).

It is an object of the present invention which is the prior art Technique inherent disadvantages and one Gear ratio switching control system for one To provide automatic vehicle transmission, which an oil pressure to the frictionally engaging elements that can guide the current Set up gear (transmission ratio), whereby the Service life of the frictionally engaging elements is improved and a smooth implementation of the next Gear shifting (changing the gear ratio) enables becomes.

The foregoing and other objects and advantages of the invention will be achieved evident from the following description and the drawings, in which:

Fig. 1 is a schematic diagram showing a gear ratio shift control / regulating system according to the present invention for a vehicle automatic transmission;

FIG. 2 is a table illustrating the engagement or disengagement of the frictionally engaging elements for respective gears (gear ratios) shown in FIG. 1;

Fig. 3 is a diagram showing part of the hydraulic circuit shown in Fig. 1;

Fig. 4 is a diagram correspondingly showing part of the hydraulic diagram shown in Fig. 1;

Fig. 5 is a table showing the energization or de-energization of the (shift) valves for the respective gears (gear ratios) shown in Fig. 1;

Fig. 6 is a flowchart showing the operation of the system shown in Fig. 1;

Figure 7 is a timing diagram representation of the operation shown in the flow chart of Figure 6;

Fig. 8 is a flowchart showing the subroutine for calculating a command QTRQ referred to in the flowchart of Fig. 6;

Fig. 9 is a graph showing the characteristics of table data of a correction quantity QTRQu referred to in the flowchart of Fig. 8;

Fig. 10 is a graph showing the characteristics of table data of a correction quantity QTRQd referred to in the flowchart of Fig. 8;

Fig. 11 is a graph showing the characteristics of table data of a correction quantity QTRQα referred to in the flowchart of Fig. 6; and

FIG. 12 is a flowchart showing the subroutine for correcting the QTRQ instruction referred to in the flowchart of FIG. 6.

With reference to the accompanying drawings, a detailed description of the preferred embodiments.

Fig. 1 is a schematic diagram showing control ratio switching / control system for an automatic vehicle transmission according to the present invention is a.

As shown, an automatic vehicle transmission 1 a hydraulic torque converter 8, the pump (not shown) to the engine output shaft 9 of an internal combustion engine 9 a is connected, and the turbine (not shown) to a transmission input shaft 8 a and first, second and third Planetary gear trains or gear trains G1, G2, G3 is connected, which are provided in a parallel arrangement on the transmission input shaft 8 a.

The first, second and third planetary gear trains G1, G2 and G3 are each with centrally positioned first, second and third Sun gears S1, S2, S3, first second and third rotating Planetary gears P1, P2, P3, with the first, second and third Combine sun gears S1, S2, S3 to rotate around them, first, second and third carriers C1, C2, C3, which the pinions P1, P2, P3 wear to allow free rotation of them while they rotate in the same way as the planet gears, and first, second and third ring gears R1, R2, R3, which a Have internal gears that with the planet gears P1, P2, P3 comb.

The first planetary gear train G1 and the second planetary gear train G2 are double pinion type planetary gear trains, and as in the diagram are shown, the first planetary gear P1 and the second planetary gear P2 each made up of two pinions P11, P12 and P21, P22.  

The first sun gear S1 is normally connected to the transmission input shaft 8 a, and the first carrier C1 is normally fixed. The first ring gear R1 is connected to the second sun gear S2 via a third hydraulic clutch K3, and it is possible to hold the second sun gear S2 in place by a first brake B1. The second carrier C2 is connected to the third carrier C3 and an output wheel 8b, whereby the rotation of the second carrier C2 and the third carrier C3 form the output rotation of the transmission.

The second ring gear R2 is directly connected to the third ring gear R3 such that the ring gears R2 and R3 as a whole can be held by a second brake B2, and these are attached to the transmission output shaft 8a such that they are attached to it by a second clutch K2 can be taken. The third sun gear S2 is attached to the transmission input shaft 8 a in such a way that it can be gripped there by a first clutch K1. A one-way clutch OWC is arranged in parallel to the second brake B2.

In the transmission described above, comprising first to third sun gears S1 to S3, first to third carriers C1 to C3 and first to third ring gears R1 to R3, the transmission input shaft 8 a and the output gear 8 b, it is possible to set up a gear (transmission ratio ) and to control the shifting to a further gear (gear ratio) by engaging or disengaging the frictionally engaging elements which are formed by the first to third clutches K1 to K3 and the first and second brakes B1 and B2. Especially when the frictionally engaging elements for engaging or disengaging are controlled as shown in Fig. 2, it is possible to have five forward gears (gear ratios) (first, second, third, fourth and fifth) and one reverse gear (gear ratio) (REVERSE) ) to set up.

Although the reduction ratios for each gear (gear ratio) change with the number of teeth of each gear, a possible example is shown in FIG. 2.

In Fig. 2, the parentheses around the second brake B2 for the first gear (gear ratio) show that even when the brake B2 is not engaged, power transmission takes place through the one-way clutch OWC. In particular, even if the second brake B2 is not put into operation when the first clutch K1 is engaged, it is possible to establish the first gear (gear ratio) and thus transmit driving force with the first gear ratio. In particular, if the second brake B2 is operated, then the first gear (gear ratio) is set up to make the engine brake effective. In the case where the first gear (gear ratio) is established without the second brake B2 applied or engaged, no engine braking effect is obtained since it is not possible to transmit the power from the wheels in this case, although the first gear (gear ratio) is established.

In order to control the supply of an oil pressure to these frictionally engaging elements, a control / regulating device 200 is provided, comprising a microcomputer, which outputs from a speed sensor 202 , comprising a magnetic pickup, which in the vicinity of the transmission input shaft 8 a for generating a signal indicating a transmission input shaft speed Nin, a speed sensor 204 , which accordingly comprises a magnetic pickup and is arranged in the vicinity of the output gear 8 b to generate a signal indicating a transmission output shaft speed Nout, and a selector lever switch 206 is obtained, which is connected to a selector lever 208 which is arranged in the vicinity of the driver's seat in order to generate a signal which corresponds to one of the gear ranges which can be selected by the driver.

In addition, the control device 200 receives outputs from a crank angle sensor 210 , which is arranged in the vicinity of the crankshaft (not shown) of the engine 9 a in order to generate a signal that represents an engine speed NE, a throttle position sensor 212 , which is in the vicinity of a throttle valve (not shown) is arranged to generate a signal which indicates an engine load by means of an opening degree θTH of a throttle valve, and a vehicle speed sensor 214 which is arranged on a drive shaft (not shown) to generate a signal which represents a driving speed V of the vehicle in which the vehicle automatic transmission 1 is mounted.

Based on the parameters thus detected, the controller excites (ON) or de-energizes (OFF) 200 solenoid valves (more specifically, switch solenoid valves) SA to SE to supply the oil pressure to the frictionally engaging elements by an oil pressure controller Circuit 300 to control / regulate as explained later. The oil pressure in the circuit 300 , as explained later, is detected by five pressure sensors PS and outputs thereof are sent to the control device 200 .

Next, a description of the oil pressure control / regulating circuit is described with reference to FIGS. 3 and 4, 300 of the first added to the engagement and disengagement to third clutches K1 to K3 and the first and second brakes B1 and B2. FIGS. 3 and 4 show parts of the oil pressure control / regulating circuit 300. In each of the drawings, ends of the oil passages, which are identified by circled letters, connect to respective, appropriately marked routes in the other drawing. Furthermore, the symbol "x" in the drawings denotes the openings which are open to drainage.

The operation of the brakes and clutches for controlling the gear shifting (gear ratios) is performed using the oil pressure from the pressurized oil supplied from the oil reservoir shown in the lower part of FIG. 3 by an oil pump 10 .

The pressure oil which is pumped into an oil path 12 by the pump 10 is adjusted by a regulator valve 14 in such a way that it has a predetermined line pressure. When pressure oil is pumped through the pump 10 , part of this oil is directed to the oil path 12 and the rest is directed to an oil path 16 through the regulator valve 14 . The pressurized oil that is routed to the oil path 16 is then routed to control the torque converter lockup clutch (not shown). The pressure oil, which is led to an oil path 18 , is returned to the oil reservoir via a relief valve (not shown).

The pressurized oil in the oil path 12 , which has been adjusted to have the prescribed line pressure as described above, is directed to the relevant parts of the oil pressure control circuit so that it is used to control the gearshifts in the automatic transmission becomes. Among the essential parts are a manual valve 20 which is connected to the selector lever 208 which is arranged in the vicinity of the driver's seat to enable the five (shift) solenoid valves SA to SE to be operated, which are controlled by the above-described control / Control device are controllable such that they are energized (ON) or de-energized (OFF), depending on parameters, including the range selection of the driver, six hydraulically operated valves 22 , 24 , 26 , 28 , 30 , 32 , which in Working in response to the operation of the manual valve 20 and the energization / de-energization of the solenoid valves SA to SE, four pressure accumulators 34 , 36 , 38 , 40 and the five oil pressure sensors PS.

The solenoid valves SA and SC are normally open type valves which are open when the electromagnetic solenoids provided therein are OFF (de-energized). On the other hand, the solenoid valves SB, SD and SE are normally closed type valves which are closed when the electromagnetic solenoids provided therein are OFF. By the controlled / regulated supply of pressure oil through the valves 20 , SA to SE, 22 , 24 , 26 , 28 , 30 and 32 , the control device 200 controls the gear shifting and the operation of the lock-up clutch of the torque converter. Fig. 5 shows the relationship between the operation of each solenoid valve SA to SE and the gears (gear ratios) established in response to these operations.

The Fig. 5 refers to ON (energization) and OFF (deenergization) -To the electromagnetic solenoids stands each solenoid valve SA to SE. The controller 200 controls the solenoids based on a duty cycle (pulse width modulation, ie ON time in a pulse train (current)) to enable a desired gear shift characteristic to be obtained.

The following is a description of the gear (gear ratio) shift control.

First, the case will be described in which the D range is selected using the selector lever so that a slide 20 a of the manual valve 20 is moved to the position corresponding to the D range.

That is, as shown in Fig. 4, when the hook portion at the right end of the slider 20 a is moved to the right to the position indicated for D3 or D2, then the connection between an oil path 42 and the oil path 12 is made, which with the pressure oil set to the prescribed line pressure is supplied. Further, since the oil path 12 is connected to the solenoid valve SC and since the oil path 42 communicates with the solenoid valve SE, the line pressure always acts on the solenoid valve SC and the solenoid valve SE. Furthermore, the line pressure always acts on the solenoid valve SA since the oil path 42 is also in communication with the solenoid valve SA.

A branching off from the oil path 12 oil passage 12 a communicates with an oil chamber at the right end of a reverse pressure switching valve 22, a branching off from the oil path 12 oil path 12 b communicates with an oil chamber at the left end of a pressure release valve 42, and a branching off from the oil path 42 oil path 42 a is in communication with an oil chamber at the right end of an output gear control valve 26 . Therefore, the line pressure causes the reverse pressure switching valve 22 and the output speed control valve 26 to normally be shifted to the left and the pressure release valve 24 to be shifted normally to the right.

In the case where the D range is selected, the controller 200 determines a gear (gear ratio) in response to the engine load and the vehicle speed, and to obtain such gear (gear ratio), the control operations are each Solenoid valve SA to SE shown in Fig. 5.

The following are the operations of the clutches and brakes described, which accompany the operations of the solenoid valves, wherein as Example is the case where the gear shift  (Gear ratio shift) is carried out to third gear (Gear ratio).

In this case, the solenoid valves SC and SD are to be switched from their ON state to their OFF state, so that all the solenoid valves SA to SE are in their OFF state. In this way, the solenoid valve SC is changed from the state described above for the second gear to be opened, whereas the solenoid valve SD is changed to be closed. Since the solenoid valve SA is kept open, the first clutch remains engaged. Since the solenoid valve SD is closed, the oil path 54 through the solenoid valve SD is in communication with the drainage, whereby the first brake B1 is released or released.

On the other hand, when the solenoid valve SC is opened, pressurized oil is supplied to the oil path 52 at the line pressure so that the third clutch K3 is engaged. At this time, a fourth accumulator 40 serves to intercept the accompanying shock. The first clutch K1 and the third clutch K3 are thus engaged to establish the third gear (gear ratio). In third gear (gear ratio), the solenoid valve SD is controlled so that it is closed so that the oil pressure, which acts on the left end of the pressure release valve 28 via the oil paths 54 , 54 b, drops to zero. However, the slide 28 a is held in its right position by the pressure oil supplied via the oil path 78 . Therefore, in the same manner as above for the second gear (gear ratio), when the solenoid valve SE is switched to its ON state, it becomes possible to control the lock-up clutch by the pressure output from the solenoid valve SE.

As stated above, the clutches and brakes indented / disengaged to shift up or down to effect.

The operating mode of the gear ratio switching control system for an automatic vehicle transmission is as follows explained using the example of the upshift, in particular the Power upshifting (of upshifting if that Throttle valve is open beyond a predetermined value).

FIG. 6 is a flowchart showing the operation of the system, which is performed by the control / regulating device 200, in particular the operation.

The program starts at S10, where it is determined whether a Upshift command, for example an upshift command from second gear to third gear is issued and if that If the result is affirmative, then the program goes to S12, where that Solenoid valve SE is switched OFF (de-energized) to the To disengage or release the lock-up clutch.

The program then goes to S14, where a timer (down counter) is included a predetermined value T1 is started to timed out measure to S16, where it is determined whether the counter value T1 reaches zero in other words, it is determined whether the predetermined time T1 has expired. The predetermined time T1 is set to a time that is long enough to fully disengage the lock-up clutch, before in the clutch oil supply control described below will occur.

If the result is affirmative, then the program goes to S18 where a period or time starting from this step as STEP1  is referred to and the task to be carried out there as JOBE referred to as.

FIG. 7 is a timing diagram illustrating the procedures or tasks performed in the flow chart of FIG. 6. As shown, the time period after the time T1 has elapsed is called STEP1 or LEVEL1.

The program then goes to S20 where an Torque reduction command for the oil supply QTRQ determined or is calculated.

Fig. 8 is a flowchart showing the subroutine for calculating the torque-down command for the oil supply QTRQ.

The program starts at S100, where an initial value QTRQO of the torque-down command for the oil supply QTRQ is calculated as follows.

QTRQO = RESLOPE × TTRQABS + RECONTACT + CR.

In this formula, RESLOPE is a coefficient for the calculation, TTRQABS a basic value, which in response to the Machine output torque is determined, in particular a value which of table data, not shown, using the detected engine speed NE and the intake vacuum PBA (by receive a sensor (not shown)) as address data, RECONTACT an additional value, which for each course (Gear ratios) is prepared, and CR one Correction coefficient for throttle opening.  

The initial value of the torque reduction command for the oil supply QTRQO is determined such that an actual hatching rate eCLO (described below) for the frictionally engaging elements (Clutches or brakes), which the gear (gear ratio), that is currently set up (second) to a first desired slip ratio ECLO2 (described later) in response converges to the machine output torque.

Furthermore, the initial value QTRQO is calculated when the Program loop is executed the first time. If the Program loop is in its second or subsequent run, then the calculated initial value QTRQO is held and as that Torque reduction command used for QTRQ oil supply. Of the Initial value QTRQ is calculated to a value that one Duty cycle (for PWM) of the switching solenoid valves corresponds. In the The initial value QTRQ is simply called the description Torque reduction command for the oil supply called QTRQ.

The program then goes to S102, where it is determined whether the current gear (gear ratio) (second) is higher or higher than the next gear (gear ratio) (third) in which to shift, that is, whether the current gear is determined Gear ratio is greater than the next gear ratio. If the result is negative, which means that an upshift is indicated, then the program goes to S104, where a correction factor for the vehicle speed in upshifting QTRQu is taken from a data table (the characteristics of which are shown in Fig. 9) using the detected vehicle speed V as address data, and to S106 where the extracted data QTRQu is added to the command QTRQ to increase it.

On the other hand, if the result in S102 is affirmative, indicating a downshift, then the program goes to S108, in which another correction factor for the downshifting vehicle speed QTRQd is taken from a data table (the characteristic of which is shown in Fig. 10), using the vehicle speed V as address data, and to S110, where the extracted value QTRQd is subtracted from the command QTRQ to decrease it.

., The program If Turning now to the flowchart of Figure 6, so proceeds to S22 in which the actual clutch slip or the actual clutch slip rate e CLO of the current gear (gear ratio) (second) detected or is calculated as follows:

eCLO = (Nout / Nin) × i,

Nout is a transmission output shaft speed (the speed of the output gear 8 b), Nin is a transmission input shaft speed (the speed of the transmission input shaft 8 a) and i is the reduction ratio.

The program goes to S24, where it is determined whether the detected actual clutch slip rate eCLO is less than the first desired or target slip rate ECLO2, in particular it is determined whether the clutch of the current gear starts to slip with an amount corresponding to ECLO2. Fig. 7 shows the first target slip rate ECLO2. The first target slip rate ECLO2 is determined in response to the machine operating conditions for respective gears (gear ratios).

If the result in S24 is negative, the program goes to S18, to repeat the above procedures. If that  If the result in S24 is affirmative, then the program goes to S26 where it is determined that STEP1 has ended and a period of time after This level begins, is called STEP2 or LEVEL2 and the the task to be performed there is called JOBF.

The program then goes to S28, where a maximum hatching rate ECLOR under the detected actual slip rate of the clutch of the current gear is selected or detected in STEP1 to S30 where a second Target hatch rate ECLOref in STEP2 as well as disclosed using the detected maximum actual slip rate ECLOR and the first target slip rate ECLO2 is calculated. In particular, the second target slip rate ECLOref by calculating an average of the maximum Actual hatching rate and the first target hatching rate are determined.

The program then goes to S32, where an error or difference ECLOdif of the absolute value between the second target slip rate ECLOref and the detected maximum actual slip rate ECLOR is calculated as follows:

ECLOdif = | ECLOref - ECLOR |.

Then, a correction value QTRQα is extracted from table data, the characteristics of which are shown in Fig. 11, using the calculated difference ECLOdif as address data.

The program then goes to S34, where the correction value QTRQα is added to the QTRQ oil supply torque reduction command to enlarge the same is added. The corrected command is called the QTRQ command in STEP2 used. Thus, the command determined in the second stage is larger than that generated in the first stage. It therefore becomes possible to have a stable switching control / regulation independent of a change in Perform condition of the frictional engagement elements.  

The program then goes to S36, where the corrected command QTRQ in the Memory is saved.

The program then goes to S38 where the corrected command QTRQ in Response to the slip rate change of the clutch of the current one Gangs is corrected again.

Fig. 12 is a flowchart showing the subroutine for this correction. The program begins at S200, where the actual slip rate eCLO is subtracted from a target slip rate for the control of the one-way clutch to calculate an actual slip rate difference ECLN. Then, using the calculated difference ECLN and a coefficient KDNT, a target difference SECLO is calculated as follows:

SECLO = ECLN × KDNT / 100.

Then the program goes to S202 where there is an actual slip rate change SeCLO by computing a first order difference or one First order derivative of the actual hatching rate eCLO is determined and it becomes determines whether the target difference SeCLO is not less than the actual Hatch rate change is SeCLO. If the result is affirmative, then the program goes to S204 where a correction quantity TRQowc of the torque reduction command for the oil supply QTRQ to Reducing it is subtracted. If the result is negative, then the program goes to S206, where a correction quantity TRQowc the torque reduction command for the oil supply QTRQ to Enlarging it is added.

The program then goes to S208, where it is determined whether the calculated one Difference SECLO not less than a certain upper limit Is SECLMAX. If the result is affirmative, then you can Program to S210, where the calculated SECLO difference is on the top  Limit SECLMAX is limited. If the result is negative, then skips program S210.

Returning to the flowchart of Fig. 6 again, the program goes to S40, in which it is determined whether JOBF has ended. In particular, this is done by calculating the slip rate of the next gear clutch and determining whether the calculated slip rate of the next gear clutch exceeds a predetermined value ECLOa1 (as shown in FIG. 7).

If the result is negative, the program goes back to S28. If the result is affirmative, the program is ended.

As shown in FIG. 7, the command is determined such that the current gear clutch is disengaged or released when the slip rate of the next gear clutch exceeds the predetermined value ECLOa1.

In the event of a next upshift, the Torque reduction command for QTRQ oil supply in JOBE (STEP1) based on the command QTRQ, which is in S36 in JOBF (STEP2) has been saved.

As indicated above, the embodiment is configured to detect the actual slip rate and to correct the torque reduction command for the oil supply QTRQ in response to the difference between the detected actual slip rate and the second target slip rate in JOBF in STEP2, as in S34 shown in the flowchart of Fig. 6, and to use this command as the basis for control / regulation of a next upshift. This can prevent the clutches (and brakes) from excessively slipping, thereby extending the service life of the clutches and brakes and allowing the gear shift control sequence to be performed smoothly.

Furthermore, the command in JOBF in STEP2 is determined to be larger is as in JOBE in STEP1. This can be a stable slip and one stable switching control / regulation independent of a change in Friction of the clutches and brakes due to changes the clutch plate temperature and oil temperature, etc.

Thus, the embodiment is constructed to have a gear ratio control system in an automatic transmission ( 1 ) mounted on a vehicle, comprising: a plurality of gear trains (G1, G2, G3), which one Transfer engine torque to a drive shaft, a plurality of frictionally engaging elements (K1, K2, K3, B1, B2, OWC), which work to selectively set up a gear ratio from the gear ratios, shift solenoid valves (SA-SE), which operate in an oil pressure control / Control circuit ( 300 ) are provided, which is connected to a source of pressure oil 10 , and a switching control / regulating means (control / regulating device 200 ) for generating a shift command for upshifting from a currently established gear ratio to one next gear ratio by determining a command (QTRQ) for the solenoid valves (SA-SE) to output s of the pressure oil from the frictionally engaging elements which establish the current gear ratio so that the slip of the frictionally engaging elements is controlled and for loading the pressure oil into the frictionally engaging elements which establish the next gear ratio to which to switch , characterized in that the switching control means comprises: a first stage (STEP1, S18-S24) for determining the command (QTRQ) such that an actual slip rate of the frictionally engaging elements which establish the current gear ratio ( eCLO) converges to a first target slip rate (ECLO2), a second stage (STEP2, S26-S40) for determining the command (QTRQ) such that the actual slip rate (eCLO) of the frictionally engaging elements that set up the current gear ratio , converged to a second target hatching rate (ECLOref), determining maximum hatching rate means (S28) for determining a maximum actual slip rate (ECLOR), slip rate difference calculation means (S32) for calculating a difference (ECLOdif) between the detected maximum actual slip rate (ECLOR) and the second target slip rate (ECLOref), command correction means (S34) for correcting the command (QTRQ) in response to the calculated difference (ECLOdif) and command storage means (S36) for storing the corrected command (QTRQ) to be used as the command in the first stage in controlling the next upshift.

In the system, the command (QTRQ) is greater than in the second stage the one (QTRQ) in the first stage and the means for determining the second target hatching rate determine the second target hatching rate (ECLOref) by calculating an average of the detected maximum slip rate (ECLOR) and the first target hatching rate (ECLO2).

It should be noted that, although the Vehicle automatic transmission shown with a planetary gear system is described, the invention also in an automatic transmission can be applied which has parallel waves as it for example, in Japanese Patent Application Laid-Open 8 (1996) - 184.367 is shown.

A system for controlling the shifting of gears (gear ratios) in an automatic transmission ( 1 ) which is attached to a vehicle comprises a shift control / regulating means for generating a shift command for upshifting from a currently established gear (gear ratio) to a next gear (gear ratio) by determining a command to solenoid valves to deliver pressure oil from the frictionally engaging elements (K1, K2, K3, B1, B1, OWC) that establish the current gear (gear ratio) to provide slip control of the friction engaging elements (K1, K2, K3, B1, B2, OWC) and to direct pressure oil into the frictionally engaging elements (K1, K2, K3, B1, B2; OWC), which set up the next gear stage (transmission ratio), to switch to. The system comprises a first stage for determining the command such that an actual slip rate of the frictionally engaging elements (K1, K2, K3, B1, B2, OWC), which establish the current gear stage (transmission ratio), at a first target slip rate converges, a second stage for determining the command such that the actual slip rate of the frictionally engaging elements (K1, K2, K3, B1, B2, OWC), which establish the current gear (transmission ratio), converges to a second target slip rate , Maximum slip rate determining means for determining a maximum actual slip rate, slip rate difference calculating means for calculating a difference between the detected maximum actual slip rate and the second target slip rate, command correcting means for correcting the command in response to the calculated difference, and command storing means for storing the corrected command, which as the command in the first stage when controlling next upshift is to be used. This arrangement can avoid that the clutches (and brakes) (K1, K2, K3, B1, B2, OWC) have excessive slippage, thereby prolonging the service life of the clutches and brakes and controlling the shifting in the next Walk gently.

Claims (3)

A system for controlling / regulating the switching of gear ratios in an automatic transmission ( 1 ) which is attached to a vehicle, comprising:
a plurality of gear trains (G1, G2, G3), which transmit the machine torque to a drive shaft,
a plurality of frictionally engaging elements (K1, K2, K3, B1, B2, OWC) which work to selectively set up a gear ratio of the gear ratios,
Shift solenoid valves (SA-SE) which are provided in an oil pressure control circuit ( 300 ) which is connected to a source of pressure oil ( 10 ), and
Shift control means (control means 200 ) for generating a shift command to shift up from a currently established gear ratio to a next gear ratio by determining a command (QTRQ) to the solenoid valves (SA-SE) to discharge the pressure oil from the frictionally engaging elements which establish the current gear ratio in order to perform a slip control of the frictionally engaging elements and for loading the pressure oil to the frictionally engaging elements which establish the next gear ratio in which to shift, characterized in that the shifting Control means include:
a first stage (STEP1, S18-S24) for determining the command (QTRQ) such that an actual slip rate of the frictionally engaging elements which establish the current transmission ratio (eCLO) converges to a first target slip rate (ECLO2),
a second stage (STEP2, S26-S40) for determining the command (QTRQ) in such a way that the actual slip rate (eCLO) of the frictionally engaging elements which establish the current transmission ratio converges to a second target slip rate (ECLOref),
Maximum slip rate determination means (S28) for determining a maximum actual slip rate (ECLOR),
Hatching rate difference calculation means (S32) for calculating a difference (ECLOdif) between the detected maximum actual hatching rate (ECLOR) and the second desired hatching rate (ECLOref),
Command correcting means (S34) for correcting the command (QTRQ) in response to the calculated difference (ECLOdif), and
Command storage means (S36) for storing the corrected command (QTRQ) to be used as the command in the first stage in controlling a next upshift. 2. System according to claim 1, characterized in that the command (QTRQ) in the second stage is larger than that (QTRQ) in the first stage. 3. System according to claim 1 or claim 2, characterized in that the means for determining the second target slip rate the second Target hatch rate (ECLOref) by calculating an average of the detected maximum slip rate (ECLOR) and the first Calculate the target hatching rate (ECLO2).